SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad63ba374140f86c46086a32818c16bc026cd2650538f001e0b00bb4560c73bc' 
  AND token = 'FQHJ6MN5x/YXQfZbGIPLXblSxXT2Be5fk1NL2UaGMCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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