SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e41f549de943736cdb1b371a8741fb4740fe23a9126f0351f3c6a9b0ff9d0f59' 
  AND token = 'xXPcvwfUWy7HIkjiP0giH/BL38zFEgfHSXO+t+gMGEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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