SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afd2095bb9acef29c7d40a2bbdc2205df2b37c9270a011a9516594ca22c86889' 
  AND token = 'sKYHRiaqe/1OvlraY/XE29HnqSmtHCAvfcuevKNKDxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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