SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf4d1fd98a2d2cdb657eb68d49c254401033c8d606f1b252bef631cc0feb2bb9' 
  AND token = '9avw1IklEQijKO0xkRZzqlwZ/KVoLwIYOEMYZHkIKg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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