SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2504a9f78b10984e2094fa6054ba5d56dfa05af24cbf936eb158468f28977369' 
  AND token = 'Ll2QxYLbHUEzi5shPNURU4hAPaYIUByyeCGNvQGAvHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}