SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44f8d0910d6b23922a97f24284ea7b307e4b2ddcaa5f3339c6e28c564ed77c0' 
  AND token = 'nDHGGKp/pBnhOVMCw2q66uE+/V5UN7AruNujEEt65wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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