SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bec038ede9c0cd9d35e3662bc6df582523fddc970bbe4b354f7429ba54db96' 
  AND token = 'ywDEKS6GQlzMKnx+P3TZift1ReBs+4vSv770iVLgokE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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