SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2e3228bf6a489f25b2e912f6637da564c090145fd37fd7f2823159f75a0729d' 
  AND token = 'opKISSOSZrsVhWdGrb2BYgNtYMPaIP/Zt4IUQCUNBIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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