SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac1af4381c274b4cd569a6c5aefee101bc5a66173df149bfc1c7e6e7b37deb4a' 
  AND token = 'NTWmrJIWOdwoAJSjCXcCJXpMtVbNzs9EeXWEDXH3aUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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