SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fa31ad10156616843527530b8df9ff991fd723dda764e387a699c5cb67fc8219' 
  AND token = 'XJq+cmpTL4sszyS63wn3cWhUe5ZnXJg83n1z8DDwWGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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