SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b9aaa3423d9629e17c520749b629252a00e0679e1bfb3d8f7caae141fad4bdd3' 
  AND token = 'ai9+UaArAU32kq/e1p4n5fWV1NhzU3iV/5sQTnWBjMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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