SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97548e1db920c2cbc3153b0344d2d08c09b8313cd435ffe4582b67f71dc96726' 
  AND token = '2hYa29RMFDaG0iimI7MDRlK+TYjvz2A8ZKp0/FGqTeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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