SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc33bfa424091070a47e79fe25fb26ccdb26b3f836299468232f1ee128d9c462' 
  AND token = 'k0gaoPvwdRm31AOAlGscUanPwoKbRYwAPgN3OlClCY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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