SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db971946877244b9f158df0270e28812e61773dd3ac6c92a45cdc41c5e1cfc0' 
  AND token = 'qDv0qlNZzi+Y9aq+gCPMaB/Vb/M5FC/JZ3uwU5/JaFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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