SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00904786691b481a99c9db66f408ef5f676e5b07efd0ad9234cbc9e6b97c4e27' 
  AND token = 'XqY1dfoEKjBo50vlnZoVIhlsV6gZBdeg2qHprnE/kWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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