SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba9851c115f11cebb1f65b17e5924ec12c54976181527b1a815144175bf8d35' 
  AND token = '7lOPt7OAExzqF1l0rrOy+gGYlO7mjDm99u6c8H0NBno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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