SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b48ee18cf2181fe43bf3c65424cc876a0c30f09f23db8d859c1b4bfc115c6d6' 
  AND token = 'b/lU5wBJikfvQmv/QJqykVBO4WtkjqS+dEDPlZ06g0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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