SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98846b1aa2809d72296955b8ada373154c4981ece1ee31426bb22d39bd343767' 
  AND token = 'dM94TTcgtNbzFcgFz50qbjOU4ZKrbSapMUqkU2s2bro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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