SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '37962d4f173f2bb1219d666dc2ace1550a7941b7e179a74670e412c9eb05dc0f' 
  AND token = 'ujiYxFyKTcRgB01/D64nByNZrptBlZgQuAtdFnUCuX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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