SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f54f0713b1d0627503e5cead8538b9f7d998a306422d45810e02ee48770c93e4' 
  AND token = 'qgqED+c71evNMJQ3pLH/SzvjXqLecf6LwnOtNTAtCcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}