SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0b170b968e66d3a0d8c99f5da5f13368f82c814d0ce6e6eec54adac20591980' 
  AND token = '7bq247YKx8Eqne91eIe7qpuZZlPZbxh6bV+LnTC8BA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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