SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '200294abbc61610f46c30a15c85d72e9328972124d8de873dea9cea952e5b63d' 
  AND token = 'DBVy+oG0RevG9GvAKq/dwh0APC263gQJGnuOpr4PjK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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