SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a60319d8f33fbd9280bbc3cb85db446a894ca5232a5774c55825ecf68b997471' 
  AND token = '0timvWVUMvsJqDCUgXY4D5k0lxbc/X4QkpXKyaM11Xo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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