SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbc9246727fed5036a0471d57fcab1d17347bd0a902f732b85bf09c770177753' 
  AND token = 'GyzH4tAdTaE2YPNP64pfz+qOEnxAHoA1FQUdZLG/PSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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