SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5932057774e548da791016b9734e6a3625f6f53f017766f26e542630ff74c2b' 
  AND token = '+0Av28xZZoSKnQefKnoALJKie5lLrLrPjngtEXqyd/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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