SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2c66e657950f032c8245b8905b5fc0dfbae4191525bec704773d182d4d260c6' 
  AND token = 'hPwPvdH6moHDL2uSsQKszEzOZKuc0qPgr1Gk23baD7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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