SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '134c7be4c3f847923a6a1425f285a52cefa6f1e3656a0acf2ba1dc4824983846' 
  AND token = 'wx5NL2AlXk/DyA3PUhxr03dhz5XR7jPhBTUn1J90+cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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