SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccbaae77fc4a105b1f01acbda903cab76959ab4004f69222ff72e7d68ae6d669' 
  AND token = 'iVm7dnr+nqjj96UsOsSQGvCln01l+kjyBH2wwwJnTJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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