SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f08d4c289d88f5c138edf2435a5cf25400617cc203fb27b2d6e6772fac872d4a' 
  AND token = 'UfUXdQIoVZDlDNiDKWGypQGOoGqBUc21IEr5EK26P/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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