SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a53e23cc94efc1ab3435a368559da9e9977e16b801bde5eb92c2825d22468a4e' 
  AND token = 'CG+hUZasGn3/ntb4WycPHVU6/XzO/kf98tip66fZysQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}