SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32a0856dd5d9b48ef1d4c1b3c7e70647091f63b25b1919b6b6da1122b7efe7c7' 
  AND token = 'OIzs3F3q7GKRBXTCKxgQuktNiOMoYY6moZ2F4LPTpUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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