SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd09a79bd3e82c791d7a161162f4f312c3627f5924fa9d0937832d95d17551731' 
  AND token = 'QANEFDWrWY3SgZ3Ssl4sVGhgTPEmwcfqlA8jFlKlrV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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