SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d0393ae132d0a6f1e9b065e4044e6f97620645594cd30e168305accce775569' 
  AND token = 'IGOj8vv+CCBqIe1vbju1WUVuZ3ZotRuLG05xRAXAcNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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