SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a9f0c7d98c14cadf5fcf94cbd9e84211bc44ca4949f1afabe3f76428585777e6' 
  AND token = 'iFlNTZ/OCnd+DR1wDl8Ij2urgwAzW5V8SPjwpTGYQqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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