SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c7583b290facbf7a384ef1a43678823e471fdd0c63719b303daf42e656386830' 
  AND token = '+n7dvbTrehFgf6zZJgIf2Ii47LL/u42QKOmO9F0CLxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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