SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6acc12d95c12c02762af3513597c75886e4b7906d04e73754f76573223d653c0' 
  AND token = 'by93ogcK2WSANICwDDVrJU0f5hudhyixzTkJa7stAhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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