SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bf55280970c94209eb9816e3cb4673b26c5640b2a4b1219099e965596085257' 
  AND token = 'eYOg9eWJDTaDV7g5GlhsmTED64BZwFk56H8PHCeUtVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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