SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '290b5dba1e44c45e528d95f97b4d4cee8f92556ab47f621e93acaf585dea851a' 
  AND token = '3WSOtjotuaF8JG5FAjWD3askREL7BBMCVtpRorqp4ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}