SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45640b80e7105abf444f334873251dca940127c66941fea83d53f7bc0fa9f967' 
  AND token = 'wQ8KLQxqGofSPzyhJbGKwk1kl9BCcffMUo4xFN6ujkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}