SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e94f6011e44ecb2daa4d5b6edc6efb5de2feb9059080837937cdc613fbf2308e' 
  AND token = 'C59O4GPpPsgsvi55OBxrHYZ4vTsQ6j0NOsDdiPAAtx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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