SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac860bcc48e88739a50382d6072681b515a55892f6f1b7c6a1acadd27b7b0c77' 
  AND token = 'JmUbcffE6MxdHzvzjfoEDX2f+422T2nClQLvffStuig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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