SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '859ef63c2be96efb2f28573598ce92b23f15f3fbcdbbcff73896e789157aa059' 
  AND token = 'GXvy4vpiRN3LXX217OrOh/x2JnH4aE+UvmKawLws1zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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