SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f23390e70f8e105adb092f15981e52e954d3e61621479cdb8b794c7035b6f93' 
  AND token = '5KkM5rmdWZB7e7fQf2ljhvz958t+EPeIVqDZzSVelVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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