SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd8cf4cb0650f0c8df1d436eb2209e3d78ecde2b3d4494b3b6be2450b5477f6f2' 
  AND token = 'tGm+etYCZmofFhbL/IY3vIFJp1KRh1ddE5evEDh5SrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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