SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1e7fbfa3e01df11bd2475dbc5ec1f153c5ec5e40d79fb088bedba48e7aeb115' 
  AND token = 'aUYP2tI2PRhm8O793Lj/spsjYXljEnD48qP4oAkEG/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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