SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '43ee3a69a993666c5410dbcfb38798994022c7825cf25a7a9524cc4c54c55c7c' 
  AND token = 'V6Sr4KEL3v+30TjgGQagEpxnE4JTX4ZlgXvnwYxwKBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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