SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d44770efe90a8118057fb12ae40a7f965ab46869085868fb636eca815df698b' 
  AND token = 'xB66FLxixIGLM8psYlT8TcvmVOfgFOLjAl06kTWA1IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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