SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42d24f2f62857f9d3058956119c62e6bcfeb282c0c90bd737379e6548c0097fc' 
  AND token = 'rGeBuJo/dKCSHxiOx2kdqrUIdYvPyzs9IkqpzL+K0oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00112

JSON explain

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