SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3bcbbe278c5f1e8e53cc15a1bb9e59f3c1f5ddafe486e35305196d71387ebad' 
  AND token = 'CYhDEK62JEAwRoBLvqWGmen5OBc8BV5STDY+XGQJCXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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