SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bc1e88b3f892fad760ec361c5627e52c2e90f5c87ae2cb41eee499b40ef4af0' 
  AND token = '39u4WWJpGlqgvQMBhm4hGtLLFZWTS7KYwQH2sJfJSuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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