SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '72ecf42dc9c92a381ec54596248e54df376dfbf760d0892706890bad323c5447' 
  AND token = 'u7vOd4kSCGPHtlzpaFJsw1P1d+1Mc7E/r0Cl9hc4H+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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