SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f8ec11dac91ca6b3d4a52a7f22003afbe4405564d8cf5cab855235b1b7fe8e6' 
  AND token = '3hg0YTRfMWpS4HtvZr/LH2iPYwjHEWLVvkQX1h6rZzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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