SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9f8f125854ad92a23451038718907712eec4060df27e1531859d433509aa061' 
  AND token = 'NbiXOl4ffxEkjagd3ixizuGHAJNxubNBCxurqMT1i/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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