SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '145ca2577b8bad500bf4b3bbe0b574d29de5759d5131bf21e37a5f55d5aff73a' 
  AND token = '1cSnxgqYWKG+f71xH5mnrW20RoNwOgsZm6ELAW2l+mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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