SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6440b325689418e81b3e7091717a1a9dc763f43a77c73d8327dbeabeb2d4c4c2' 
  AND token = 'jnREEcl4ElN7vb22YXBEyKa5VsTuF8JyicKdn11IeV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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