SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f89f6522c1f33891164913abda95ec09bc7f0be1966808abb717f9eb7df5e3a' 
  AND token = 'M7nrrNpeQGAOsIab3TnxTEOpcXXWmeOMyo4prBrt/9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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