SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff1c4a675b96d4e93a698d4b762bc262e8e3f6d40b24a0cd8d48fefb93adfd62' 
  AND token = 'xzAbyX+h2vmF7CU9OfQJLHrJ2s9Hncz73ykcQLcogCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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