SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f8b1c7fcd079f2d2cb2291e032383afb96ae0978e747902b41181a9ab5180d0' 
  AND token = 'KIo0JTHIuTjvwK16PlGJJQM7hgm83nZu4wB0lD+k+Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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