SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1334ff50c1f1ba9e4cf8f46a57cd486e372f72d17165f265c74c043a70da1d49' 
  AND token = '8mSTx2rU33x4sV+i+mi4IlHK1Oo/TXJD54hmOgS/H1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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