SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83ef343cfce10da84d6d15c6360b49725bd491483b37138138eee25ce5007498' 
  AND token = 'Y6EtSh3F2PHHpUrovdGYqC0N3OQvSt4jhhhHXYAuFFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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