SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b88a75111a4a274a7f127664d4bb14165f803e835096a8dd651cbd6fb1b3d465' 
  AND token = 'RBlVZnjB2MF95OwnwUIy5qIXcPoArDVzSJ8Om+r/bVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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