SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e30620c0cbb8bd44da533f804fa901429c93f4a698d445fce94ae92398851de' 
  AND token = 'z/gbp2tTLhcAOqpLhbg+i91qHTxVvgvN/jvJYSIa7LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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